The family of a 30-year-old Crystal Palace woman who died tragically from rare “death in bed syndrome” linked to her diabetes have paid tribute to a “caring, loving sister, daughter and friend”.

Lyndsay Allen, from Central Hill, died in her sleep in the arms of her long term boyfriend on August 31 after spending a night out celebrating a friend’s birthday.

Today an inquest into her death found she did not die from high or low levels of sugar in her blood, but from an extremely rare and unexplained condition found among diabetes sufferers under 40 where, according to coroner Paul Knapman, “tragically one day you just do not wake up.”

The inquest at Westminster Coroner’s Court today heard how she had at times struggled to control her diabetes, but had taken insulin the night before she died and had tested her blood sugar levels and found they were normal.

Miss Allen, who had drunk alcohol but not at a level which could cause a toxic reaction, was found dead by her boyfriend, Michael Phillips in his flat in Wimbledon at 10.30am.

The inquest heard how Mr Phillips, who was found by police in a state of shock, had been woken hours before by her snoring.

After the inquest her sisters Catherine, 34, and Louise, 32, paid tribute to her: They said: “She was a very wonderful, caring, loving sister, daughter and friend and she was much loved by people around her.

“There were so many people at her funeral and it was standing room only - she had touched so many people.

“Although she had a difficult time with diabetes, she never let it get on top of her and she lived her life as normally as she could.”

They said they only realised quite how much it was a part of her life when they checked her diary after her death and found countless doctors' appointments.

Just a month before her death she had celebrated her 30th birthday with all her friends and family, and that was the last time her parents, who live near Wigan, had seen her.

Mr Knapman gave her cause of death as natural causes as a result of “sudden unexpected death in diabetes”.

He called the death a tragedy adding: “Here is a girl of only 30 years with her whole life ahead of her and she has died suddenly for no reason.”